package cn.lcsjsxy.yxz.day.Set;

import java.util.HashMap;
import java.util.HashSet;

//HashMap
public class HashMap1 {

    public static void main(String[] args) {

        //
        HashMap map = new HashMap();

        //添加数据
        map.put("a","1");
        System.out.println(map.put("a","4"));
        map.put("b","2");
        map.put("c","3");

        //查询数据
        System.out.println(map.get("a"));
        //删除
        map.remove("a");

        System.out.println(map);
    }

}
